Also "modern" landfills when filled tend to be "capped" (covered in plastic) so rain doesn't leach though into the groud water. If they have a bottom liner, these landfills are like the worlds largest plastic bags.
To prevent methane building inside the capped landfill, pipes are run and the gas is collected and sometimes "flared" [1]
Having dug into some old old landfills, it was like a time machine of 25+ year old stuff. nothing seems to rot well inside them (no water). papers readable. We found a glass bottle of what appeared to be grape soda.
Also "modern" landfills when filled tend to be "capped" (covered in plastic) so rain doesn't leach though into the groud water. If they have a bottom liner, these landfills are like the worlds largest plastic bags.
To prevent methane building inside the capped landfill, pipes are run and the gas is collected and sometimes "flared" [1]
Having dug into some old old landfills, it was like a time machine of 25+ year old stuff. nothing seems to rot well inside them (no water). papers readable. We found a glass bottle of what appeared to be grape soda.
[1]https://www.epa.gov/lmop/basic-information-about-landfill-ga...